This is a revised application for a Mentored Research Scientist Development Award (K01). The proposed career development plan will enhance the PI's experience and competencies in five main areas related to anxiety disorder treatment development and evaluation. The PI will work closely with mentors to: (1) develop and participate in mentored didactic, treatment, and research activities intended to enhance the applicant's knowledge of anxiety and the psychopathology and treatment of anxiety disorders, (2) develop and participate in activities to improve the applicant's methodological knowledge and skills relating to programmatic clinical outcome research design and evaluation, (3) acquire and enhance the statistical skills necessary to effective carry out the complex multivariate analyses required in sophisticated treatment outcome research, (4) undertake mentored activities to improve the applicant's abilities to develop and implement externally-funded programs of research on the psychopathology and treatment of anxiety disorder, and (5) training in the responsible conduct of research. The proposed training plan will facilitate the PI in the development of a long-term research program examining efficient and efficacious transdiagnostic cognitive-behavioral treatments for anxiety. The objectives of the proposed research plan are to examine the efficacy of a transdiagnostic anxiety treatment versus a credible attention-placebo condition, assessing outcome at multiple follow-up periods, and evaluating if there is differential outcome by anxiety diagnosis or other client characteristic. If anticipated results are not obtained, the proposed project would still provide valuable data regarding important categories or dimensions along which clients must be divided for effective treatment. However, should anticipated results be obtained, the proposed project would represent a major step toward fulfilling the long- term goals of this research program.